blown midbass?
 

This happend about a year ago. I was installing a deck (Didn't disconnect battery) oops!. I grounded out my speakers, I heard a pop noise in my speakers.

I turned the car back on and it seemed like the midbass/midrange was really low and I could mostly hear the high's. I wonder if it affected the crossover or my speakers.

Any ides?

^ It could also be the amp too.

I would bench test the mid/midbass speaker, or try another speaker and see if its the same thing.

the x-over should be fine in most cases.

12v will not blow a speaker. we do that to speakers all day to check the polarity. check the wiring ! make shure your x over is all conected and check resistance across the voice coil